The viewfinders are squinty. If they weren't, camera makers wouldn't have made them larger to fix this problem. ;)
The LTM Leicas are to rangefinders what the Exaktas are to SLRs. Historically important and finely made sure -but clumsy in use. You have to deal with all of their archaic idiosyncrasies when shooting. Can you make excellent photos with them? Certainly. You can also make excellent photos with lots of other cameras with less fuss though. The primary reason to use them so far as I can see is simply for the experience.